The invention relates to a driving device for a shut-off device in a pipe-line.
Driving devices of this general type are used for shut-off devices, which are used in pipe-lines of plants predominantly in the chemical and foodstuffs industries, but also in mining, in cement, textile or wood-processing plants. These shut-off devices serve in particular as a protection against explosions. At the time of propagation of a flame detected in the pipe-line or at the time of a sudden increase in pressure, the shut-off device is closed within a very short closing time, and consequently propagation of flames and thus an explosion can be prevented.
In a known shut-off device for protection against explosions according to DE-C2-30 07 689, a piston/cylinder unit actuating the shut-off device is connected by way of a line to a pressure medium reservoir, which can be opened by way of a valve. The piston and with it the slide valve plate can thus be closed in the manner of a projectile. The pressure medium reservoir is in this case manufactured from a special construction and in the operating state has a pressure of up to 40 bars. In order to absorb the impact energy produced on the slide valve plate at the time of closing of this type, coupling member inserted between the piston and the slide valve plate is constructed so that at the time of closing it strikes against a support, which consists of plastically deformable, non-elastic material and becomes permanently deformed upon impact of the coupling member. Accordingly, this support as well as the pressure reservoir must be exchanged after each impact.